Human health is impacted by a variety of microbial organisms. Inoculation of humans or other mammals by these microorganisms often results in various sicknesses and ailments. Public awareness of such contaminations has been heightened due to the increased number of food poisonings, streptococcal infections, etc. which have been occurring in the recent past. Consequently, there has been a thrust by the medical community to persuade the general public to wash any areas which generally come in contact with infected surfaces like body parts (e.g. hand washing), foods (e.g., uncooked meat, vegetables, fruits, etc.), cooking utensils, cooking surfaces (e.g., counter tops, sinks, etc.). It has been found that such methods are important in attempts to remove pathogenic microorganisms from human skin as well as other surfaces.
The types of microorganisms which can be found on mammalian skin include viruses, bacteria, and fungi. In general, virologists agree that rhinoviruses, influenza viruses, and adenoviruses are most likely the most relevant viruses which cause respiratory diseases. It is believed that rhinoviruses, in particular, are responsible for acting as the primary cause for the common cold. Rhinoviruses are members of the picornavirus family. As such they are referred to as "naked viruses" since they lack an outer envelope. Such picomaviruses are known to be difficult to inactivate by commonly used means like quaternary ammonium compounds.
Rhinovirus infections are spread from person to person by means of virus-contaminated respiratory secretions. Evidence suggests that the primary mode of transmission is via direct contact, as opposed to inhalation of airborne viral particles. It has been demonstrated that ill persons have a propensity to contaminate their hands and environmental objects. Rhinovirus has been recovered from 40 to 90% of hands of persons experiencing colds and from 6 to 15% of diverse objects. Rhinovirus exhibits good survival on many environmental surfaces for hours after contamination, and infection is readily transmitted by finger-to-finger contact and by finger to contaminated environmental surface if the newly contaminated finger is then used to rub an eye or touch the nasal mucosa.
Since a substantial proportion of rhinovirus colds are transmitted by direct contact from virus-contaminated hands or objects, it is possible to lower the risk of acquiring infection by inactivating virus on hands or surfaces. A common household phenol/alcohol disinfectant has been shown to be effecting in disinfecting contaminated environmental surfaces but lacks residual virucidal effects. Hand washing is highly effective at disinfecting contaminated fingers but again suffers from a lack of residual activity. These shortcomings provide strong opportunities for improved virucidal technologies with residual activity against rhinoviruses.
It has been found that iodine is an effective anti-viral agent and provides residual anti-rhinoviral activity on skin. In experimentally induced and natural cold transmission studies, subjects who used iodine products had significantly fewer colds than placebo users. This indicates that iodine is effective for prolonged periods at blocking the transmission of rhinoviral infections. Thus, the development of hand products, lotions, or washes (without the associated color or odor negatives of iodine) that deliver both immediate and residual anti-viral activity would be effective in reducing the incidents of colds. Likewise, a topical product which exhibits anti-viral activity would be effective in preventing and/or treating virus-induced diseases caused by other viruses like adenoviruses, rotaviruses, herpes viruses, respiratory syncytial viruses, coronaviruses, parainfluenza viruses, enteroviruses, influenza viruses, etc.
With regard to bacteria, there are two types. Resident bacteria are Gram positive bacteria which are established as permanent microcolonies on the surface and outermost layers of mammalian skin. Such bacteria play an important role in preventing the colonization of other more harmful bacteria and fungi. Transient bacteria, however are not part of the normal resident flora of the skin but they can be deposited when airborne contaminated material lands on the skin or when contaminated material is brought into physical contact with it. Transient bacteria are typically divided into two subclasses: Gram positive and Gram negative. Gram positive bacteria include pathogens such as Staphylococcus aureus, Streptococcus pyogenes and Clostridium botulinum. Gram negative bacteria include pathogens such as Salmonella, Escherichia coli, Klebsiella, Haemophilus, Pseudomonas aeruginosa, Proteus and Shigella dysenteriae. Gram negative bacteria are generally distinguished from Gram positive by an additional protective cell membrane which generally results in the Gram negative bacteria being less susceptible to topical antibacterial actives.
As with viruses, the types of bacteria that can infect humans and other mammals are innumerable. As a result, a number of products have been developed over the years which are effective for providing immediate antimicrobial efficacy, that is, anti-viral and/or antibacterial efficacy. These products range from personal cleansing products such as hand soaps to household cleaning products like disinfectant sprays and cleansers. Most of these products, however, fail to provide residual activity or efficacy against pathogenic viruses and bacteria to the areas they are used to treat. A need, however, still remains for compositions and products which provide not only improved immediate anti-viral and/or antibacterial efficacy but improved residual efficacy and antifungal efficacy as well. There is also a need to provide improved immediate anti-viral (e.g., anti-rhinoviral) activity, and antibacterial activity in water based systems (i.e., non-alcohol). There is an additional need to provide compositions and products which exhibit improved antifungal efficacy.
Applicants have found that the compositions of the present invention which comprise a benzoic acid analog, a metal salt, and a carrier wherein the composition has a pH of from about 1 to about 7 are effective in providing not only improved immediate anti-viral and/or antibacterial efficacy but also desirable improved residual efficacy.